The Russian Government has ordered five biggest firms to limit foreign currency reserves in order to support the rouble.

      Five of the country's biggest exporters have been instructed to reduce their foreign currency assets to October levels and not raise them until March. They are three energy companies Gazprom, Rosneft and Zarubezhneft, and diamond businesses Alrosa and Kristall.

      The latest measures have been taken by Russian authorities as an attempt to support the rouble which last week hit a record low against the dollar. Last week, the Russians needed 70 roubles to buy a single dollar.

      Some economists say the latest measures were effectively a version of capital controls, designed to prevent foreign currency from leaving Russia.

      In December 2014, sliding oil prices and sanctions over Russia's stance on Ukraine have caused the fall of the Russian rouble and pushed the country's economy towards recession. Russia's Central Bank has made a difficult decision to raise its key interest rate to 17%, to help prop up the rouble.